diff --git a/.github/workflows/analyze.yml b/.github/workflows/analyze.yml index 2a905a0df..b1ef428d0 100644 --- a/.github/workflows/analyze.yml +++ b/.github/workflows/analyze.yml @@ -11,18 +11,26 @@ jobs: analyze: runs-on: ubuntu-latest steps: - - uses: actions/checkout@v3 + - uses: actions/checkout@v4 - name: Set up node - uses: actions/setup-node@v3 + uses: actions/setup-node@v4 with: node-version: '20.x' + cache: yarn + cache-dependency-path: yarn.lock - - name: Install dependencies - uses: bahmutov/npm-install@v1.7.10 + - name: Restore cached node_modules + uses: actions/cache@v4 + with: + path: "**/node_modules" + key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }} + + - name: Install deps + run: yarn install --frozen-lockfile - name: Restore next build - uses: actions/cache@v3 + uses: actions/cache@v4 id: restore-build-cache env: cache-name: cache-next-build @@ -41,7 +49,7 @@ jobs: run: npx -p nextjs-bundle-analysis@0.5.0 report - name: Upload bundle - uses: actions/upload-artifact@v3 + uses: actions/upload-artifact@v4 with: path: .next/analyze/__bundle_analysis.json name: bundle_analysis.json @@ -73,7 +81,7 @@ jobs: run: ls -laR .next/analyze/base && npx -p nextjs-bundle-analysis compare - name: Upload analysis comment - uses: actions/upload-artifact@v3 + uses: actions/upload-artifact@v4 with: name: analysis_comment.txt path: .next/analyze/__bundle_analysis_comment.txt @@ -82,7 +90,7 @@ jobs: run: echo ${{ github.event.number }} > ./pr_number - name: Upload PR number - uses: actions/upload-artifact@v3 + uses: actions/upload-artifact@v4 with: name: pr_number path: ./pr_number diff --git a/.github/workflows/site_lint.yml b/.github/workflows/site_lint.yml index 34ca6d7b8..36f7642c9 100644 --- a/.github/workflows/site_lint.yml +++ b/.github/workflows/site_lint.yml @@ -14,14 +14,22 @@ jobs: name: Lint on node 20.x and ubuntu-latest steps: - - uses: actions/checkout@v1 + - uses: actions/checkout@v4 - name: Use Node.js 20.x - uses: actions/setup-node@v3 + uses: actions/setup-node@v4 with: node-version: 20.x + cache: yarn + cache-dependency-path: yarn.lock - - name: Install deps and build (with cache) - uses: bahmutov/npm-install@v1.8.32 + - name: Restore cached node_modules + uses: actions/cache@v4 + with: + path: "**/node_modules" + key: node_modules-${{ runner.arch }}-${{ runner.os }}-${{ hashFiles('yarn.lock') }} + + - name: Install deps + run: yarn install --frozen-lockfile - name: Lint codebase run: yarn ci-check diff --git a/public/.well-known/atproto-did b/public/.well-known/atproto-did new file mode 100644 index 000000000..ad8b0a36b --- /dev/null +++ b/public/.well-known/atproto-did @@ -0,0 +1 @@ +did:plc:uorpbnp2q32vuvyeruwauyhe \ No newline at end of file diff --git a/src/components/Icon/IconBsky.tsx b/src/components/Icon/IconBsky.tsx new file mode 100644 index 000000000..6645152dd --- /dev/null +++ b/src/components/Icon/IconBsky.tsx @@ -0,0 +1,24 @@ +/* + * Copyright (c) Facebook, Inc. and its affiliates. + */ + +import {memo} from 'react'; + +export const IconBsky = memo(function IconBsky( + props +) { + return ( + + + + ); +}); diff --git a/src/components/Layout/Footer.tsx b/src/components/Layout/Footer.tsx index 679be185e..d63e437cd 100644 --- a/src/components/Layout/Footer.tsx +++ b/src/components/Layout/Footer.tsx @@ -8,6 +8,7 @@ import cn from 'classnames'; import {ExternalLink} from 'components/ExternalLink'; import {IconFacebookCircle} from 'components/Icon/IconFacebookCircle'; import {IconTwitter} from 'components/Icon/IconTwitter'; +import {IconBsky} from 'components/Icon/IconBsky'; import {IconGitHub} from 'components/Icon/IconGitHub'; export function Footer() { @@ -374,6 +375,12 @@ export function Footer() { className={socialLinkClasses}> + + + {title &&
{title}
} {children} -
+
{twitter && (
@@ -77,7 +80,7 @@ export function TeamMember({ {threads && (
@@ -85,6 +88,17 @@ export function TeamMember({
)} + {bsky && ( +
+ + + {bsky} + +
+ )} {github && (
+ +The React team is excited to share new updates: + + + +1. We're publishing React Compiler Beta today, so that early adopters and library maintainers can try it and provide feedback. +2. We're officially supporting React Compiler for apps on React 17+, through an optional `react-compiler-runtime` package. +3. We're opening up public membership of the [React Compiler Working Group](https://github.com/reactwg/react-compiler) to prepare the community for gradual adoption of the compiler. + +--- + +At [React Conf 2024](/blog/2024/05/22/react-conf-2024-recap), we announced the experimental release of React Compiler, a build-time tool that optimizes your React app through automatic memoization. [You can find an introduction to React Compiler here](/learn/react-compiler). + +Since the first release, we've fixed numerous bugs reported by the React community, received several high quality bug fixes and contributions[^1] to the compiler, made the compiler more resilient to the broad diversity of JavaScript patterns, and have continued to roll out the compiler more widely at Meta. + +In this post, we want to share what's next for React Compiler. + +## Try React Compiler Beta today {/*try-react-compiler-beta-today*/} + +At [React India 2024](https://www.youtube.com/watch?v=qd5yk2gxbtg), we shared an update on React Compiler. Today, we are excited to announce a new Beta release of React Compiler and ESLint plugin. New betas are published to npm using the `@beta` tag. + +To install React Compiler Beta: + + +npm install -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta + + +Or, if you're using Yarn: + + +yarn add -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta + + +You can watch [Sathya Gunasekaran's](https://twitter.com/_gsathya) talk at React India here: + + + +## We recommend everyone use the React Compiler linter today {/*we-recommend-everyone-use-the-react-compiler-linter-today*/} + +React Compiler’s ESLint plugin helps developers proactively identify and correct [Rules of React](/reference/rules) violations. **We strongly recommend everyone use the linter today**. The linter does not require that you have the compiler installed, so you can use it independently, even if you are not ready to try out the compiler. + +To install the linter only: + + +npm install -D eslint-plugin-react-compiler@beta + + +Or, if you're using Yarn: + + +yarn add -D eslint-plugin-react-compiler@beta + + +After installation you can enable the linter by [adding it to your ESLint config](/learn/react-compiler#installing-eslint-plugin-react-compiler). Using the linter helps identify Rules of React breakages, making it easier to adopt the compiler when it's fully released. + +## Backwards Compatibility {/*backwards-compatibility*/} + +React Compiler produces code that depends on runtime APIs added in React 19, but we've since added support for the compiler to also work with React 17 and 18. If you are not on React 19 yet, in the Beta release you can now try out React Compiler by specifying a minimum `target` in your compiler config, and adding `react-compiler-runtime` as a dependency. [You can find docs on this here](/learn/react-compiler#using-react-compiler-with-react-17-or-18). + +## Using React Compiler in libraries {/*using-react-compiler-in-libraries*/} + +Our initial release was focused on identifying major issues with using the compiler in applications. We've gotten great feedback and have substantially improved the compiler since then. We're now ready for broad feedback from the community, and for library authors to try out the compiler to improve performance and the developer experience of maintaining your library. + +React Compiler can also be used to compile libraries. Because React Compiler needs to run on the original source code prior to any code transformations, it is not possible for an application's build pipeline to compile the libraries they use. Hence, our recommendation is for library maintainers to independently compile and test their libraries with the compiler, and ship compiled code to npm. + +Because your code is pre-compiled, users of your library will not need to have the compiler enabled in order to benefit from the automatic memoization applied to your library. If your library targets apps not yet on React 19, specify a minimum `target` and add `react-compiler-runtime` as a direct dependency. The runtime package will use the correct implementation of APIs depending on the application's version, and polyfill the missing APIs if necessary. + +[You can find more docs on this here.](/learn/react-compiler#using-the-compiler-on-libraries) + +## Opening up React Compiler Working Group to everyone {/*opening-up-react-compiler-working-group-to-everyone*/} + +We previously announced the invite-only [React Compiler Working Group](https://github.com/reactwg/react-compiler) at React Conf to provide feedback, ask questions, and collaborate on the compiler's experimental release. + +From today, together with the Beta release of React Compiler, we are opening up Working Group membership to everyone. The goal of the React Compiler Working Group is to prepare the ecosystem for a smooth, gradual adoption of React Compiler by existing applications and libraries. Please continue to file bug reports in the [React repo](https://github.com/facebook/react), but please leave feedback, ask questions, or share ideas in the [Working Group discussion forum](https://github.com/reactwg/react-compiler/discussions). + +The core team will also use the discussions repo to share our research findings. As the Stable Release gets closer, any important information will also be posted on this forum. + +## React Compiler at Meta {/*react-compiler-at-meta*/} + +At [React Conf](/blog/2024/05/22/react-conf-2024-recap), we shared that our rollout of the compiler on Quest Store and Instagram were successful. Since then, we've deployed React Compiler across several more major web apps at Meta, including [Facebook](https://www.facebook.com) and [Threads](https://www.threads.net). That means if you've used any of these apps recently, you may have had your experience powered by the compiler. We were able to onboard these apps onto the compiler with few code changes required, in a monorepo with more than 100,000 React components. + +We've seen notable performance improvements across all of these apps. As we've rolled out, we're continuing to see results on the order of [the wins we shared previously at ReactConf](https://youtu.be/lyEKhv8-3n0?t=3223). These apps have already been heavily hand tuned and optimized by Meta engineers and React experts over the years, so even improvements on the order of a few percent are a huge win for us. + +We also expected developer productivity wins from React Compiler. To measure this, we collaborated with our data science partners at Meta[^2] to conduct a thorough statistical analysis of the impact of manual memoization on productivity. Before rolling out the compiler at Meta, we discovered that only about 8% of React pull requests used manual memoization and that these pull requests took 31-46% longer to author[^3]. This confirmed our intuition that manual memoization introduces cognitive overhead, and we anticipate that React Compiler will lead to more efficient code authoring and review. Notably, React Compiler also ensures that *all* code is memoized by default, not just the (in our case) 8% where developers explicitly apply memoization. + +## Roadmap to Stable {/*roadmap-to-stable*/} + +*This is not a final roadmap, and is subject to change.* + +We intend to ship a Release Candidate of the compiler in the near future following the Beta release, when the majority of apps and libraries that follow the Rules of React have been proven to work well with the compiler. After a period of final feedback from the community, we plan on a Stable Release for the compiler. The Stable Release will mark the beginning of a new foundation for React, and all apps and libraries will be strongly recommended to use the compiler and ESLint plugin. + +* ✅ Experimental: Released at React Conf 2024, primarily for feedback from early adopters. +* ✅ Public Beta: Available today, for feedback from the wider community. +* 🚧 Release Candidate (RC): React Compiler works for the majority of rule-following apps and libraries without issue. +* 🚧 General Availability: After final feedback period from the community. + +These releases also include the compiler's ESLint plugin, which surfaces diagnostics statically analyzed by the compiler. We plan to combine the existing eslint-plugin-react-hooks plugin with the compiler's ESLint plugin, so only one plugin needs to be installed. + +Post-Stable, we plan to add more compiler optimizations and improvements. This includes both continual improvements to automatic memoization, and new optimizations altogether, with minimal to no change of product code. Upgrading to each new release of the compiler is aimed to be straightforward, and each upgrade will continue to improve performance and add better handling of diverse JavaScript and React patterns. + +Throughout this process, we also plan to prototype an IDE extension for React. It is still very early in research, so we expect to be able to share more of our findings with you in a future React Labs blog post. + +--- + +Thanks to [Sathya Gunasekaran](https://twitter.com/_gsathya), [Joe Savona](https://twitter.com/en_JS), [Ricky Hanlon](https://twitter.com/rickhanlonii), [Alex Taylor](https://github.com/alexmckenley), [Jason Bonta](https://twitter.com/someextent), and [Eli White](https://twitter.com/Eli_White) for reviewing and editing this post. + +--- + +[^1]: Thanks [@nikeee](https://github.com/facebook/react/pulls?q=is%3Apr+author%3Anikeee), [@henryqdineen](https://github.com/facebook/react/pulls?q=is%3Apr+author%3Ahenryqdineen), [@TrickyPi](https://github.com/facebook/react/pulls?q=is%3Apr+author%3ATrickyPi), and several others for their contributions to the compiler. + +[^2]: Thanks [Vaishali Garg](https://www.linkedin.com/in/vaishaligarg09) for leading this study on React Compiler at Meta, and for reviewing this post. + +[^3]: After controlling on author tenure, diff length/complexity, and other potential confounding factors. \ No newline at end of file diff --git a/src/content/blog/index.md b/src/content/blog/index.md index 4a1a165a3..e37631e80 100644 --- a/src/content/blog/index.md +++ b/src/content/blog/index.md @@ -10,6 +10,12 @@ This blog is the official source for the updates from the React team. Anything i
+ + +We announced an experimental release of React Compiler at React Conf 2024. We've made a lot of progress since then, and in this post we want to share what's next for React Compiler ... + + + Last week we hosted React Conf 2024, a two-day conference in Henderson, Nevada where 700+ attendees gathered in-person to discuss the latest in UI engineering. This was our first in-person conference since 2019, and we were thrilled to be able to bring the community together again ... diff --git a/src/content/community/acknowledgements.md b/src/content/community/acknowledgements.md index 9a981efd5..760076d83 100644 --- a/src/content/community/acknowledgements.md +++ b/src/content/community/acknowledgements.md @@ -4,7 +4,7 @@ title: Acknowledgements -React was originally created by [Jordan Walke.](https://github.com/jordwalke) Today, React has a [dedicated full-time team working on it](/community/team), as well as over a thousand [open source contributors.](https://github.com/facebook/react/blob/main/AUTHORS) +React was originally created by [Jordan Walke.](https://github.com/jordwalke) Today, React has a [dedicated full-time team working on it](/community/team), as well as over a thousand [open source contributors.](https://github.com/facebook/react/graphs/contributors) diff --git a/src/content/community/team.md b/src/content/community/team.md index 6004476e2..407448f48 100644 --- a/src/content/community/team.md +++ b/src/content/community/team.md @@ -18,7 +18,7 @@ Current members of the React team are listed in alphabetical order below. Andrew got started with web development by making sites with WordPress, and eventually tricked himself into doing JavaScript. His favorite pastime is karaoke. Andrew is either a Disney villain or a Disney princess, depending on the day. - + Dan got into programming after he accidentally discovered Visual Basic inside Microsoft PowerPoint. He has found his true calling in turning [Sebastian](#sebastian-markbåge)'s tweets into long-form blog posts. Dan occasionally wins at Fortnite by hiding in a bush until the game ends. @@ -42,7 +42,7 @@ Current members of the React team are listed in alphabetical order below. Josh majored in Mathematics and discovered programming while in college. His first professional developer job was to program insurance rate calculations in Microsoft Excel, the paragon of Reactive Programming which must be why he now works on React. In between that time Josh has been an IC, Manager, and Executive at a few startups. outside of work he likes to push his limits with cooking. - + Lauren's programming career peaked when she first discovered the `` tag. She’s been chasing that high ever since. She studied Finance instead of CS in college, so she learned to code using Excel instead of Java. Lauren enjoys dropping cheeky memes in chat, playing video games with her partner, and petting her dog Zelda. @@ -62,7 +62,7 @@ Current members of the React team are listed in alphabetical order below. Noah’s interest in UI programming sparked during his education in music technology at NYU. At Meta, he's worked on internal tools, browsers, web performance, and is currently focused on React. Outside of work, Noah can be found tinkering with synthesizers or spending time with his cat. - + Ricky majored in theoretical math and somehow found himself on the React Native team for a couple years before joining the React team. When he's not programming you can find him snowboarding, biking, climbing, golfing, or closing GitHub issues that do not match the issue template. diff --git a/src/content/learn/react-compiler.md b/src/content/learn/react-compiler.md index 5afaa4cf5..df46954d2 100644 --- a/src/content/learn/react-compiler.md +++ b/src/content/learn/react-compiler.md @@ -3,7 +3,7 @@ title: React Compiler --- -This page will give you an introduction to the new experimental React Compiler and how to try it out successfully. +This page will give you an introduction to React Compiler and how to try it out successfully. @@ -13,18 +13,34 @@ These docs are still a work in progress. More documentation is available in the * Getting started with the compiler -* Installing the compiler and eslint plugin +* Installing the compiler and ESLint plugin * Troubleshooting -React Compiler is a new experimental compiler that we've open sourced to get early feedback from the community. It still has rough edges and is not yet fully ready for production. +React Compiler is a new compiler currently in Beta, that we've open sourced to get early feedback from the community. While it has been used in production at companies like Meta, rolling out the compiler to production for your app will depend on the health of your codebase and how well you’ve followed the [Rules of React](/reference/rules). + +The latest Beta release can be found with the `@beta` tag, and daily experimental releases with `@experimental`. -React Compiler is a new experimental compiler that we've open sourced to get early feedback from the community. It is a build-time only tool that automatically optimizes your React app. It works with plain JavaScript, and understands the [Rules of React](/reference/rules), so you don't need to rewrite any code to use it. +React Compiler is a new compiler that we've open sourced to get early feedback from the community. It is a build-time only tool that automatically optimizes your React app. It works with plain JavaScript, and understands the [Rules of React](/reference/rules), so you don't need to rewrite any code to use it. + +The compiler also includes an [ESLint plugin](#installing-eslint-plugin-react-compiler) that surfaces the analysis from the compiler right in your editor. **We strongly recommend everyone use the linter today.** The linter does not require that you have the compiler installed, so you can use it even if you are not ready to try out the compiler. + +The compiler is currently released as `beta`, and is available to try out on React 17+ apps and libraries. To install the Beta: + + +npm install -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta + -The compiler also includes an [eslint plugin](#installing-eslint-plugin-react-compiler) that surfaces the analysis from the compiler right in your editor. The plugin runs independently of the compiler and can be used even if you aren't using the compiler in your app. We recommend all React developers to use this eslint plugin to help improve the quality of your codebase. +Or, if you're using Yarn: + + +yarn add -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta + + +If you are not using React 19 yet, please see [the section below](#using-react-compiler-with-react-17-or-18) for further instructions. ### What does the compiler do? {/*what-does-the-compiler-do*/} @@ -32,6 +48,10 @@ In order to optimize applications, React Compiler automatically memoizes your co The compiler uses its knowledge of JavaScript and React's rules to automatically memoize values or groups of values within your components and hooks. If it detects breakages of the rules, it will automatically skip over just those components or hooks, and continue safely compiling other code. + +React Compiler can statically detect when Rules of React are broken, and safely opt-out of optimizing just the affected components or hooks. It is not necessary for the compiler to optimize 100% of your codebase. + + If your codebase is already very well-memoized, you might not expect to see major performance improvements with the compiler. However, in practice memoizing the correct dependencies that cause performance issues is tricky to get right by hand. @@ -94,19 +114,9 @@ However, if `expensivelyProcessAReallyLargeArrayOfObjects` is truly an expensive So if `expensivelyProcessAReallyLargeArrayOfObjects` was used in many different components, even if the same exact items were passed down, that expensive calculation would be run repeatedly. We recommend [profiling](https://react.dev/reference/react/useMemo#how-to-tell-if-a-calculation-is-expensive) first to see if it really is that expensive before making code more complicated. -### What does the compiler assume? {/*what-does-the-compiler-assume*/} - -React Compiler assumes that your code: - -1. Is valid, semantic JavaScript -2. Tests that nullable/optional values and properties are defined before accessing them (for example, by enabling [`strictNullChecks`](https://www.typescriptlang.org/tsconfig/#strictNullChecks) if using TypeScript), i.e., `if (object.nullableProperty) { object.nullableProperty.foo }` or with optional-chaining `object.nullableProperty?.foo` -3. Follows the [Rules of React](https://react.dev/reference/rules) - -React Compiler can verify many of the Rules of React statically, and will safely skip compilation when it detects an error. To see the errors we recommend also installing [eslint-plugin-react-compiler](https://www.npmjs.com/package/eslint-plugin-react-compiler). - ### Should I try out the compiler? {/*should-i-try-out-the-compiler*/} -Please note that the compiler is still experimental and has many rough edges. While it has been used in production at companies like Meta, rolling out the compiler to production for your app will depend on the health of your codebase and how well you've followed the [Rules of React](/reference/rules). +Please note that the compiler is still in Beta and has many rough edges. While it has been used in production at companies like Meta, rolling out the compiler to production for your app will depend on the health of your codebase and how well you've followed the [Rules of React](/reference/rules). **You don't have to rush into using the compiler now. It's okay to wait until it reaches a stable release before adopting it.** However, we do appreciate trying it out in small experiments in your apps so that you can [provide feedback](#reporting-issues) to us to help make the compiler better. @@ -114,37 +124,32 @@ Please note that the compiler is still experimental and has many rough edges. Wh In addition to these docs, we recommend checking the [React Compiler Working Group](https://github.com/reactwg/react-compiler) for additional information and discussion about the compiler. -### Checking compatibility {/*checking-compatibility*/} - -Prior to installing the compiler, you can first check to see if your codebase is compatible: - - -npx react-compiler-healthcheck@experimental - - -This script will: - -- Check how many components can be successfully optimized: higher is better -- Check for `` usage: having this enabled and followed means a higher chance that the [Rules of React](/reference/rules) are followed -- Check for incompatible library usage: known libraries that are incompatible with the compiler +### Installing eslint-plugin-react-compiler {/*installing-eslint-plugin-react-compiler*/} -As an example: +React Compiler also powers an ESLint plugin. The ESLint plugin can be used **independently** of the compiler, meaning you can use the ESLint plugin even if you don't use the compiler. -Successfully compiled 8 out of 9 components. -StrictMode usage not found. -Found no usage of incompatible libraries. +npm install -D eslint-plugin-react-compiler@beta -### Installing eslint-plugin-react-compiler {/*installing-eslint-plugin-react-compiler*/} - -React Compiler also powers an eslint plugin. The eslint plugin can be used **independently** of the compiler, meaning you can use the eslint plugin even if you don't use the compiler. +Then, add it to your ESLint config: - -npm install eslint-plugin-react-compiler@experimental - +```js +import reactCompiler from 'eslint-plugin-react-compiler' + +export default [ + { + plugins: { + 'react-compiler': reactCompiler, + }, + rules: { + 'react-compiler/react-compiler': 'error', + }, + }, +] +``` -Then, add it to your eslint config: +Or, in the deprecated eslintrc config format: ```js module.exports = { @@ -152,14 +157,16 @@ module.exports = { 'eslint-plugin-react-compiler', ], rules: { - 'react-compiler/react-compiler': "error", + 'react-compiler/react-compiler': 'error', }, } ``` -The eslint plugin will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase. +The ESLint plugin will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase. -**You don't have to fix all eslint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized, but it is not required to fix everything before you can use the compiler. + +**You don't have to fix all ESLint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized, but it is not required to fix everything before you can use the compiler. + ### Rolling out the compiler to your codebase {/*using-the-compiler-effectively*/} @@ -176,77 +183,75 @@ const ReactCompilerConfig = { }; ``` -In rare cases, you can also configure the compiler to run in "opt-in" mode using the `compilationMode: "annotation"` option. This makes it so the compiler will only compile components and hooks annotated with a `"use memo"` directive. Please note that the `annotation` mode is a temporary one to aid early adopters, and that we don't intend for the `"use memo"` directive to be used for the long term. - -```js {2,7} -const ReactCompilerConfig = { - compilationMode: "annotation", -}; - -// src/app.jsx -export default function App() { - "use memo"; - // ... -} -``` - When you have more confidence with rolling out the compiler, you can expand coverage to other directories as well and slowly roll it out to your whole app. #### New projects {/*new-projects*/} If you're starting a new project, you can enable the compiler on your entire codebase, which is the default behavior. -## Usage {/*installation*/} +### Using React Compiler with React 17 or 18 {/*using-react-compiler-with-react-17-or-18*/} -### Babel {/*usage-with-babel*/} +React Compiler works best with React 19 RC. If you are unable to upgrade, you can install the extra `react-compiler-runtime` package which will allow the compiled code to run on versions prior to 19. However, note that the minimum supported version is 17. -npm install babel-plugin-react-compiler@experimental +npm install react-compiler-runtime@beta -The compiler includes a Babel plugin which you can use in your build pipeline to run the compiler. - -After installing, add it to your Babel config. Please note that it's critical that the compiler run **first** in the pipeline: +You should also add the correct `target` to your compiler config, where `target` is the major version of React you are targeting: -```js {7} +```js {3} // babel.config.js -const ReactCompilerConfig = { /* ... */ }; +const ReactCompilerConfig = { + target: '18' // '17' | '18' | '19' +}; module.exports = function () { return { plugins: [ - ['babel-plugin-react-compiler', ReactCompilerConfig], // must run first! - // ... + ['babel-plugin-react-compiler', ReactCompilerConfig], ], }; }; ``` -`babel-plugin-react-compiler` should run first before other Babel plugins as the compiler requires the input source information for sound analysis. +### Using the compiler on libraries {/*using-the-compiler-on-libraries*/} -React Compiler works best with React 19 RC. If you are unable to upgrade, you can install the extra `react-compiler-runtime` package which will allow the compiled code to run on versions prior to 19. However, note that the minimum supported version is 17. +React Compiler can also be used to compile libraries. Because React Compiler needs to run on the original source code prior to any code transformations, it is not possible for an application's build pipeline to compile the libraries they use. Hence, our recommendation is for library maintainers to independently compile and test their libraries with the compiler, and ship compiled code to npm. + +Because your code is pre-compiled, users of your library will not need to have the compiler enabled in order to benefit from the automatic memoization applied to your library. If your library targets apps not yet on React 19, specify a minimum [`target` and add `react-compiler-runtime` as a direct dependency](#using-react-compiler-with-react-17-or-18). The runtime package will use the correct implementation of APIs depending on the application's version, and polyfill the missing APIs if necessary. + +Library code can often require more complex patterns and usage of escape hatches. For this reason, we recommend ensuring that you have sufficient testing in order to identify any issues that might arise from using the compiler on your library. If you identify any issues, you can always opt-out the specific components or hooks with the [`'use no memo'` directive](#something-is-not-working-after-compilation). + +Similarly to apps, it is not necessary to fully compile 100% of your components or hooks to see benefits in your library. A good starting point might be to identify the most performance sensitive parts of your library and ensuring that they don't break the [Rules of React](/reference/rules), which you can use `eslint-plugin-react-compiler` to identify. + +## Usage {/*installation*/} + +### Babel {/*usage-with-babel*/} -npm install react-compiler-runtime@experimental +npm install babel-plugin-react-compiler@beta -You should also add the correct `target` to your compiler config, where `target` is the major version of React you are targeting: +The compiler includes a Babel plugin which you can use in your build pipeline to run the compiler. -```js {3} +After installing, add it to your Babel config. Please note that it's critical that the compiler run **first** in the pipeline: + +```js {7} // babel.config.js -const ReactCompilerConfig = { - target: '18' // '17' | '18' | '19' -}; +const ReactCompilerConfig = { /* ... */ }; module.exports = function () { return { plugins: [ - ['babel-plugin-react-compiler', ReactCompilerConfig], + ['babel-plugin-react-compiler', ReactCompilerConfig], // must run first! + // ... ], }; }; ``` +`babel-plugin-react-compiler` should run first before other Babel plugins as the compiler requires the input source information for sound analysis. + ### Vite {/*usage-with-vite*/} If you use Vite, you can add the plugin to vite-plugin-react: @@ -273,36 +278,7 @@ export default defineConfig(() => { ### Next.js {/*usage-with-nextjs*/} -Next.js has an experimental configuration to enable the React Compiler. It automatically ensures Babel is set up with `babel-plugin-react-compiler`. - -- Install Next.js canary, which uses React 19 Release Candidate -- Install `babel-plugin-react-compiler` - - -npm install next@canary babel-plugin-react-compiler@experimental - - -Then configure the experimental option in `next.config.js`: - -```js {4,5,6} -// next.config.js -/** @type {import('next').NextConfig} */ -const nextConfig = { - experimental: { - reactCompiler: true, - }, -}; - -module.exports = nextConfig; -``` - -Using the experimental option ensures support for the React Compiler in: - -- App Router -- Pages Router -- Webpack (default) -- Turbopack (opt-in through `--turbo`) - +Please refer to the [Next.js docs](https://nextjs.org/docs/canary/app/api-reference/next-config-js/reactCompiler) for more information. ### Remix {/*usage-with-remix*/} Install `vite-plugin-babel`, and add the compiler's Babel plugin to it: @@ -335,40 +311,7 @@ export default defineConfig({ ### Webpack {/*usage-with-webpack*/} -You can create your own loader for React Compiler, like so: - -```js -const ReactCompilerConfig = { /* ... */ }; -const BabelPluginReactCompiler = require('babel-plugin-react-compiler'); - -function reactCompilerLoader(sourceCode, sourceMap) { - // ... - const result = transformSync(sourceCode, { - // ... - plugins: [ - [BabelPluginReactCompiler, ReactCompilerConfig], - ], - // ... - }); - - if (result === null) { - this.callback( - Error( - `Failed to transform "${options.filename}"` - ) - ); - return; - } - - this.callback( - null, - result.code, - result.map === null ? undefined : result.map - ); -} - -module.exports = reactCompilerLoader; -``` +A community Webpack loader is [now available here](https://github.com/SukkaW/react-compiler-webpack). ### Expo {/*usage-with-expo*/} @@ -392,22 +335,26 @@ To report issues, please first create a minimal repro on the [React Compiler Pla You can also provide feedback in the React Compiler Working Group by applying to be a member. Please see [the README for more details on joining](https://github.com/reactwg/react-compiler). -### `(0 , _c) is not a function` error {/*0--_c-is-not-a-function-error*/} +### What does the compiler assume? {/*what-does-the-compiler-assume*/} -This occurs if you are not using React 19 RC and up. To fix this, [upgrade your app to React 19 RC](https://react.dev/blog/2024/04/25/react-19-upgrade-guide) first. +React Compiler assumes that your code: + +1. Is valid, semantic JavaScript. +2. Tests that nullable/optional values and properties are defined before accessing them (for example, by enabling [`strictNullChecks`](https://www.typescriptlang.org/tsconfig/#strictNullChecks) if using TypeScript), i.e., `if (object.nullableProperty) { object.nullableProperty.foo }` or with optional-chaining `object.nullableProperty?.foo`. +3. Follows the [Rules of React](https://react.dev/reference/rules). -If you are unable to upgrade to React 19, you may try a userspace implementation of the cache function as described in the [Working Group](https://github.com/reactwg/react-compiler/discussions/6). However, please note that this is not recommended and you should upgrade to React 19 when possible. +React Compiler can verify many of the Rules of React statically, and will safely skip compilation when it detects an error. To see the errors we recommend also installing [eslint-plugin-react-compiler](https://www.npmjs.com/package/eslint-plugin-react-compiler). ### How do I know my components have been optimized? {/*how-do-i-know-my-components-have-been-optimized*/} [React Devtools](/learn/react-developer-tools) (v5.0+) has built-in support for React Compiler and will display a "Memo ✨" badge next to components that have been optimized by the compiler. ### Something is not working after compilation {/*something-is-not-working-after-compilation*/} -If you have eslint-plugin-react-compiler installed, the compiler will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase. **You don't have to fix all eslint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized. +If you have eslint-plugin-react-compiler installed, the compiler will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase. **You don't have to fix all ESLint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized. Due to the flexible and dynamic nature of JavaScript however, it's not possible to comprehensively detect all cases. Bugs and undefined behavior such as infinite loops may occur in those cases. -If your app doesn't work properly after compilation and you aren't seeing any eslint errors, the compiler may be incorrectly compiling your code. To confirm this, try to make the issue go away by aggressively opting out any component or hook you think might be related via the [`"use no memo"` directive](#opt-out-of-the-compiler-for-a-component). +If your app doesn't work properly after compilation and you aren't seeing any ESLint errors, the compiler may be incorrectly compiling your code. To confirm this, try to make the issue go away by aggressively opting out any component or hook you think might be related via the [`"use no memo"` directive](#opt-out-of-the-compiler-for-a-component). ```js {2} function SuspiciousComponent() { diff --git a/src/content/reference/react/useReducer.md b/src/content/reference/react/useReducer.md index 40c88c164..8e8d20e8c 100644 --- a/src/content/reference/react/useReducer.md +++ b/src/content/reference/react/useReducer.md @@ -52,7 +52,7 @@ function MyComponent() { #### Caveats {/*caveats*/} * `useReducer` is a Hook, so you can only call it **at the top level of your component** or your own Hooks. You can't call it inside loops or conditions. If you need that, extract a new component and move the state into it. -* The `dispatch` function has a stable identity, so you will often see it omitted from effect dependencies, but including it will not cause the effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) +* The `dispatch` function has a stable identity, so you will often see it omitted from Effect dependencies, but including it will not cause the Effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) * In Strict Mode, React will **call your reducer and initializer twice** in order to [help you find accidental impurities.](#my-reducer-or-initializer-function-runs-twice) This is development-only behavior and does not affect production. If your reducer and initializer are pure (as they should be), this should not affect your logic. The result from one of the calls is ignored. --- diff --git a/src/content/reference/react/useState.md b/src/content/reference/react/useState.md index 4aa9d5911..23db1aae5 100644 --- a/src/content/reference/react/useState.md +++ b/src/content/reference/react/useState.md @@ -85,7 +85,7 @@ function handleClick() { * React [batches state updates.](/learn/queueing-a-series-of-state-updates) It updates the screen **after all the event handlers have run** and have called their `set` functions. This prevents multiple re-renders during a single event. In the rare case that you need to force React to update the screen earlier, for example to access the DOM, you can use [`flushSync`.](/reference/react-dom/flushSync) -* The `set` function has a stable identity, so you will often see it omitted from effect dependencies, but including it will not cause the effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) +* The `set` function has a stable identity, so you will often see it omitted from Effect dependencies, but including it will not cause the Effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) * Calling the `set` function *during rendering* is only allowed from within the currently rendering component. React will discard its output and immediately attempt to render it again with the new state. This pattern is rarely needed, but you can use it to **store information from the previous renders**. [See an example below.](#storing-information-from-previous-renders) diff --git a/src/content/reference/react/useTransition.md b/src/content/reference/react/useTransition.md index 5066fe637..b6dcb3c73 100644 --- a/src/content/reference/react/useTransition.md +++ b/src/content/reference/react/useTransition.md @@ -80,7 +80,7 @@ function TabContainer() { * The function you pass to `startTransition` must be synchronous. React immediately executes this function, marking all state updates that happen while it executes as Transitions. If you try to perform more state updates later (for example, in a timeout), they won't be marked as Transitions. -* The `startTransition` function has a stable identity, so you will often see it omitted from effect dependencies, but including it will not cause the effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) +* The `startTransition` function has a stable identity, so you will often see it omitted from Effect dependencies, but including it will not cause the Effect to fire. If the linter lets you omit a dependency without errors, it is safe to do. [Learn more about removing Effect dependencies.](/learn/removing-effect-dependencies#move-dynamic-objects-and-functions-inside-your-effect) * A state update marked as a Transition will be interrupted by other state updates. For example, if you update a chart component inside a Transition, but then start typing into an input while the chart is in the middle of a re-render, React will restart the rendering work on the chart component after handling the input update. diff --git a/src/content/reference/rules/components-and-hooks-must-be-pure.md b/src/content/reference/rules/components-and-hooks-must-be-pure.md index 9da65d04a..d3d54560e 100644 --- a/src/content/reference/rules/components-and-hooks-must-be-pure.md +++ b/src/content/reference/rules/components-and-hooks-must-be-pure.md @@ -194,7 +194,7 @@ function ProductDetailPage({ product }) { } ``` -One way to achieve the desired result of updating `window.title` outside of render is to [synchronize the component with `window`](/learn/synchronizing-with-effects). +One way to achieve the desired result of updating `document.title` outside of render is to [synchronize the component with `document`](/learn/synchronizing-with-effects). As long as calling a component multiple times is safe and doesn’t affect the rendering of other components, React doesn’t care if it’s 100% pure in the strict functional programming sense of the word. It is more important that [components must be idempotent](/reference/rules/components-and-hooks-must-be-pure). diff --git a/src/sidebarBlog.json b/src/sidebarBlog.json index 26dcdc4dd..84947fdf5 100644 --- a/src/sidebarBlog.json +++ b/src/sidebarBlog.json @@ -11,6 +11,13 @@ "path": "/blog", "skipBreadcrumb": true, "routes": [ + { + "title": "React Compiler Beta Release and Roadmap", + "titleForHomepage": "React Compiler Beta Release and Roadmap", + "icon": "blog", + "date": "October 21, 2024", + "path": "/blog/2024/10/21/react-compiler-beta-release" + }, { "title": "React Conf 2024 Recap", "titleForHomepage": "React Conf 2024 Recap",